Hospitals and other medical care institutions provide differing levels of patient care so as to conserve resources, minimize the costs of patient care, and maximize patient outcomes (i.e., the condition or health of the patient). To achieve this, the attending staff will transfer a patient between different units in the hospital in accordance with the acuity of the patient's condition. For example, a high-acuity patient may be admitted to an intensive care unit (ICU) or critical care unit (CCU), then is transferred to an intermediate care unit, and so on to successively less-intensive care environments until the patient is released from the hospital. Such a paradigm of transitional medical care has been precipitated by the increasing costs of providing medical care, and the increasing acuity of the patients that receive such medical care. For example, the average acuity of the patients that are transferred to an intermediate care environment is now higher than in the past. More particularly, a patient that is transferred to an intermediate care unit is now likely to require a more intensive level of continuing care in comparison to the level of care required by such a patient in years past.
For the attending staff to successfully practice such medical care, the patient monitoring applied to each patient must be easily reconfigured according to the patient's condition, acuity, and location. However, the conventional patient monitoring system for a non-ambulatory patient typically employs a fixed, dedicated bedside monitor that is located and dedicated for use in a bedside-monitored environment. The bedside monitor is usually wall-mounted, configured for use at one bed, and hardwired to a particular hospital communications network. Such instruments are expensive, and thus typically are in short supply, and they are not easily reconfigured when the patient transfers between beds, rooms, or environments.
An ambulatory patient may be assigned a telemetry transmitter that is worn by the patient such that telemetry data is transmitted to an array of telemetry antennas and receivers, which are connected to the hospital communications network. Reconfiguring the patient monitoring system at transitions between non-ambulatory and ambulatory monitoring modes is a difficult, expensive, and time-consuming task, and typically results in a gap or discontinuity in the stream of monitor data. As a result, a conventional monitoring system is not well-suited for use in a transitional care practice.
The foregoing may thus be seen to limit the versatility and usability of the conventional patient monitoring system, especially in situations where the telemetry transmitter is the only monitoring device applied to the patient. Further, while it may be desirable to implement more capabilities in a telemetry transmitter so as to resolve such drawbacks, it is also desirable that such capabilities be achieved without any significant increase in the monitor's cost, size, weight, and power usage. As a result, the conventional patient monitoring system is not well-suited for use in a transitional care practice.
Accordingly, there is a need for network-based, system-originated control of one or more of the features, functions, or tasks performed in a patient monitoring system. A particular function that would benefit from such control is the transmission of a telemetry signal. Because hospitals and physicians are relying more often on telemetry monitoring for their patients, the quality of a telemetry signal must be excellent. Some of the problems that the attending staff will encounter while monitoring ambulatory patients is signal degradation caused by noise, fading, drop-outs, and multipath distortion. Noise is potentially present at all times on the telemetry signal because the telemetry signals must pass through an environment of interfering electrical signals of various strengths and frequencies. A degraded signal will result in discontinuous monitoring, an inability to interpret the monitored function, and false alarms.
A digital telemetry monitoring system can determine that the data in a transmission is corrupt, but it cannot eliminate the problem of interference, and therefore conventional systems do not provide a complete solution. One advance has been the provision of a telemetry system offering noise reduction that transmits in the UHF (Ultra High Frequency) band instead of the commonly used VHF (Very High Frequency) band. The HP M1403A Digital UHF Telemetry System, incorporating the benefits of UHF transmission with digital technology, currently provides a high level of immunity to electrical interference. However, these units are still susceptible to some types of intermittent interference, such as may be emitted by a radio frequency transmitter operating at the frequency used by the unit.